1. Field of the Invention
This invention relates generally to electrical connectors, and more particularly, to a modular connector with capacitive plates to reduce cross-talk.
2. Description of the Related Art
Modular connectors are widely used to provide electrical connections between devices. For example, modular plugs are typically found on telephone sets to connect the telephone to a modular jack. Modular plug and jack connectors are also commonly used to connect computer equipment.
Cables providing high speed digital signal transmission interfaces between computer equipment typically include a plurality of twisted-pair conductors. Modular connectors used at the ends of the cable are rated for their electrical performance under various operating conditions. The Telecommunications Industry Association and the Electronic Industries Association (TIA/EIA) have issued a telecommunications system bulletin specification entitled, "Additional Transmission Specifications for Unshielded Twisted-Pair connecting Hardware." The specification describes three increasing levels of performance, Category 3, Category 4, and Category 5. Category 5 connectors must meet performance specifications at up to 100 MHz frequencies and 100 Mbps transmission rates.
Industry specifications defining the cable and connector requirements have an inherent defect in the contact vs. twisted-pair arrangement. Some of the wires of the twisted-pair combinations are located in the connector next to other wires from other twisted-pairs. This arrangement increases the amount of cross-talk seen between the competing contacts. This propensity for cross-talk causes problems when trying to meet the Category 5 performance requirements.
Cross-talk can be generally described as the unwanted coupling of electrical signals on adjacent signal lines. Such cross-talk may result in portions of an electrical signal on one pair of lines appearing on a separate pair of lines as unwanted noise. Cross-talk between different pairs of wires is a source of interference that can cause signal degradation and negatively impact the ability of a communication system to process incoming signals. Cross-talk can also increase error rates and reduce signal strength. Problems associated with unwanted cross-talk are becoming even more problematic given the general increase in operating frequencies and data rates of modern communication systems. Additionally, cross-talk can be particularly problematic within electrical connectors that contain a plurality of wires that are generally parallel and spaced closely together. Such a configuration may lead to excessive cross-talk even over short conductor lengths.
Previous methods for reducing the cross-talk have included interleaving the contacts within the connector to cause coupling and reduce the amount of cross-talk. Other techniques have included using a printed-circuit board type capacitive laminate covering the parallel array of contacts. Both techniques involve costly manufacturing methods that become a major contributor to the cost of the connector.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.